A Unique Presentation of a Thoracic Conundrum: Tracheobronchial Rests in the Esophagus

Abstract

Tracheobronchial rests are a rare congenital anomaly where ectopic respiratory tract elements may be found in an abnormal site, such as within the esophageal wall. We present a case of a late presentation of an esophageal intramural tracheobronchial rest with complaints of pain in the left chest wall, vomiting, and loss of appetite for one month. The chest X-ray and mammogram were both normal, but an endoscopy could not be performed due to luminal narrowing. A CT scan shows a well-defined, round, non-enhancing hypodense lesion measuring 2.6 x 2.7 cm in the middle one-third of the esophagus. Upon resection, histopathological examination revealed fragments of tissue lined by pseudostratified ciliated columnar epithelium with respiratory mucinous glands admixed with pools of mucin and underlying strands of skeletal muscle. The subepithelium contains esophageal submucosal glands, which confirm the esophageal origin of the choristoma. The usual presentation is congenital esophageal stenosis at birth with over half of these cases being attributed to tracheobronchial rests. Presentation beyond adolescence is even rarer with a relatively benign course and favorable prognosis. Clinical, radiological, and pathological correlation as well as a high index of suspicion are important to avoid misdiagnosis and to institute optimal treatment.

Keywords: choristoma; congenital; esophageal stenosis; heterotopia; rests; tracheobronchial.

Figure 1. CT lung (transverse view) showing an esophageal mass (white arrow)

A well-defined, round, non-enhancing hypodense lesion measuring 2.6 x 2.7 cm in the para-esophageal region on the left side from the middle one-third of the esophagus

Figure 2. Non-FDG avid non-enhancing lesion (40 x 27 x 35 mm, SUV max 1.05) seen along the left lateral wall of the distal esophagus (white arrow)

Figure 3. Respiratory epithelium with underlying bundles of skeletal muscle (H&E stain at 400x magnification)

Figure 4. Respiratory epithelium and an adjacent pool of extracellular mucin containing numerous neutrophils and eosinophils (H&E stain at 400x magnification)

Figure 5. Subepithelium of the muscular fragment with an underlying submucosal gland, indicative of an esophageal origin (H&E stain at 400x magnification)